Anyone who has spent time doing design engineering knows that it is a constant battle against 'the way things are done'. Maybe not for everyone, but my roots in Physics make me take a step back and consider 'Is there a better way'. Older, more entrenched engineers don't like that. In the government I had free reign, they learned early to just let me run...

I am on the cutting edge now just like I was during the development of the Internet. I may not have made a lot of money but I have been a technical player and contributor since I was fixing my friends go-carts.

6 US patents should attest that I know a good technology when I see one. And I can think of new and different ways to use it. Doubt me at your own peril

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

Here's some meat...or maybe just fire...using a small generator to wake up a grid-tied PV system can result in a generator explosion and fire. I'm glad you know what you are doing. Remember how puny and insignificant your FF technology is to the Sun.

However, I have a standalone PV inverter that creates a grid. I can use it to wake up as many grid-tied inverters as I want (for a small fee). This is what a micro-grid is. A bunch of PV inverters with one in charge...mine.

My house inverter is not grid-tied after I disconnect from the grid via opening the main panel breaker. After I start the generator, the inverter itself monitors for 5 minutes and if the power stays within limits, comes back online, and it doesn't know whether the grid or the generator is tickling it. "Taking care" means disconnecting the generator, allowing the solar PV to power down, and then throwing the main breaker to re-connect to the grid. A proper 100-amp T-bar switch would be better and pretty foolproof, but the estimate was $1400 for that.

I don't expect to do this often or long. Nor will I even tell the new owner how. If he wants a proper T-Bar switch and a standalone inverter, or a Powerwall battery, he can pay for it.

Your system is small and your loads are big. If the PV power has no where to go it will raise it's voltage, backfeed the generator, and boom! A grid tied inverter cannot regulate it's output, the sun does that

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

Your system is small and your loads are big. If the PV power has no where to go it will raise it's voltage, backfeed the generator, and boom! A grid tied inverter cannot regulate it's output, the sun does that

Except .... it did not do that. The generator ran through one entire tank of gas, while the refrigerator cycled on and off, we used the microwave, and the coffemaker and the lights. This was from 11AM to about 3:30 PM on a September day, I had to have been producing near the full 2800 watts the whole time. Then when it ran out of gas and I was refilling the tank, I heard the neighbor's pool pump come on and I knew the grid was back on.

In fact, your description does not fit the way I understand electricity to work. The generator idles quietly with no load, then the throttle advances as you add load up to capacity, and it is producing maximum torque at that same RPM. I never even blew a fuse when I did this, nor did I expect to. Maybe the equipment I use behaves differently from that you install.

I am only repeating what I was taught. This is not something I've tried. But I would in an emergency The generator can idle all day that won't stop a backfeed. The PV would carry all the load and then backfeed any over-production. Any resistive load like a water heater element would take the over production instead. As long as there are loads taking the power it's ok.

But maintaining that balance manually long term is not possible. Something will burn up.

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

I think the key is adding constant resitive loads like incandescent lighting. It allows the generator and inverter to self-regulate. I just never heard of "backfeed' on a solid state voltage-regulated circuit like a modern inverter. That term was used in the dark ages of mechanical governors and wind turbines and hydro power and diesel generator sets, almost exclusively when one generator gets slightly out of phase with the grid. I certainly never experienced a problem with my inverter, a US-made "Sunny Boy" SMA-3000. It adjusts to load changes almost instantly, without a flicker.

In case this was not clear before, the generator set has a solid state inverter of it's own, a standalone type that regulates voltage and frequency both, as the load varies 0-500w. This is normal on cheap Chinese 2-cycle generators. They probably only last about 400 hours and are not worth rebuilding, but I have less than 10 hours on mine.

You're right KJ,Backfeed is an archaic term. It doesn't really represent what is going on. The inverter raises it's voltage (within limits) until it can push the power out. There is no battery so it all has to go out. Both the inverter and the generator have voltage limits that may not match (lack of standards). If the generator cannot handle the voltage produced by the inverter it will blow. If the inverter is unhappy it will just shut down.

A grid-tied inverter does not regulate output other than by adjusting voltage. As it raises the voltage, resistive loads will take more power (again within limits). I would bet the voltage on your micro-grid was highly unstable.

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

I don't usually blow my own horn But I do occasionally use that approach to intimidate pushy people who are standing in my way. Face to face it works very well.

But it has no relevance to the argument, I'm sorry

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

Ibon wrote:The mistake is binary thinking, creating a division when there isn't one. Both on and off grid together create a more resilient society.

How so?

It's simple. There is no ideology here. There are densities of human population all around the planet that make a combination of on grid centralized power and off grid individual power generation the most resilient solution. Sometimes a rose is just a rose, we do not need to inject politics or ideology into it.

It's like every topic has to be in the context of ones alliances with the status quo.

Why do we do this?

Our resiliency resembles an invasive weed. We are the Kudzu Apeblog: http://blog.mounttotumas.com/website: http://www.mounttotumas.com

I just looked up Hubris... (in Greek tragedy) excessive pride toward or defiance of the gods, leading to nemesis.

Replace gods with TPTB and nemesis with transition and that is me

Apology redacted.

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

I think what Ibon means is no issue is black and white, everything is a compromise. A combination of grid and off-grid supports that conclusion.

No matter what we do ideology creeps in. My driving force is efficiency. Work smarter not harder. It affects everything I do...the power of laziness

One of the bright things about this site is the lack of a 'status quo'. We get bright ideas from all directions, and some dark ones too.

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

baha wrote:No matter what we do ideology creeps in. My driving force is efficiency. Work smarter not harder. It affects everything I do...the power of laziness

That's funny. Laziness is a big critique that peakers have with those who live in the lap of luxury of our energy slaves. I thought in order to win respect from peakers you must live a hardscrabble subsistence farming lifestyle.

I talk about how things aren't that hard. One of the reasons I feel that way is I treat it like a process. Plant two rows, take a break. Harvest two rows, take a break.

My solar array took a week just for panels. Install a few panels, take a break and admire I don't see it as hard, I see it as rewarding.

The fact that the grid and the grocery store still exist takes some of the pressure off

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

This is the way physicists see the world...The possibilities are endless

A Solar fuel spill is otherwise known as a sunny day!The energy density of a tank of FF's doesn't matter if it's empty.https://monitoringpublic.solaredge.com/solaredge-web/p/kiosk?guid=19844186-d749-40d6-b848-191e899b37db

It's the nature of humanity to be problem-solvers. While it's true that kicking the can down the road (think green revolution) doesn't ultimately "solve" limits to growth, we really have no choice but to continue down the road we're on because people won't stop having babies above replacement. I don't like that situation but it would be foolish to adopt the position of a luddite who does nothing but naysay and root against technological innovation. People like that really have nothing to offer beyond their Unabomber-style fundamentalism.

I for one would just LOVE to see us manage our birthrate, but I take your point, it's not going to happen, absent some massive external stimulus such as a global famine.

A global famine is however one of the "baked in catastropies" in that other current thread. Even if we manage to run the grid on 100% renewables, both transportation and agriculture still depend almost exclusively upon liquid and gaseous FF's. Without mechanized agriculture, without cheap petroleum-sourced fertilizers/pesticides/herbicides, food production plummets to a fraction of former output. Without cheap transportation, one is reduced to eating what grows within a few hundrded miles, the range of BEV's.

Now let's talk about "we". Those societies that have a chance to survive the human famine are those that both can and do adapt to the loss of cheap FF energy. It is a popular misconception around here that the 3rd World is better prepared to ride out the famine because they have less of a dependance upon cheap energy. That is rank foolishness.

The residences of the 1st World countries are habitable even without FF power generation, and would continue to be so with a grid running on renewable energy. (Granted, your heating bill will increase.) Food processing and food preservation derive from grid energy. When food production plummets from the fossil fueled apex we are at now to some lower level, Americans and other 1st World countries will still be eating in the midst of severe economic disruption. 2nd and 3rd World countries will starve. Such countries are where FF's already make the difference between malnutrition and famine.

I contend that the present slump in oil prices is winding the spring tighter and tighter. When such prices inevitably increase in the approaching oil shortage, the 1st World will be positioned to survive, not those on the edge of starving already. As 1st World citizens, our own worst problem will not be finding enough food, it will be coping with starving refugees. Have you noticed that we already have that problem?

As I have said before many times, TEOTWAWKI is a long drawn out process that will last a century or two. I have come to believe that TEOTWAWKI actually began in the 1950's, and is now becoming more noticeable. Since then, we have more than doubled World human population, and are well on the way to tripling it.

Save yourselves, the government is not going to do so. The government exists at the beck and call of the 1%. The 1% has already positioned themselves to survive, save for the clueless trust fund babies. The next priority the government has is to save themselves, which is in fact hopeless. Saving the Middle Class is priority #3, and it will never get started, much less happen.

As to the topic of this thread, running the grid on 100% renewables is possible, in the opinion of this EE. It is also necessary to save the Middle Class. But the Barack Obama's, the Donald Trump's, the Hillary Clinton's, the Bernie Sanders, and the rest of the Criminal Class are not going to do this unless you force them to do so with your vote. There was in fact not a single major candidate who even talked about the topic. Some Greenies who never made it past round one, perhaps.

Save yourselves. Live next to food production, because even Donald Trump can't save any of the cities, including especially NYC. The global famine coming our way is a Darwinian sorting of our species. Think of it as evolution in action.

I'm still amazed how much time is spent discussing the "100%" target for renewables. Which is really focused primarily of wind and solar power...about 6% nationwide right now. Hydro and nuclear are pretty much where they are. Fantasize instead about just a 5 fold increase in wind/solar to about 30%. Think what that would do to coal and NG consumption...and prices. Think what it would do to NG drilling...for decades. But what about the intermittency problem? Well, do like Texas: use the remaining fossil fuel sources to fill the gaps. Of course if the commercial storage is ever solved it would be an easy solution since the wind/solar systems would already exist.